Originally Posted by ksio89
I accessed the Testing menu through the number *#*#4636#*#*, and on "Phone information" submenu, there's a toggle called "VoLTE provisioned", and it was turned on. Does this confirms my phone has 4G+ support on software level, but the device is blacklisted by the carrier?
The capability resides first of all in the hardware so no problem in that cause SD630 supports it, but the second scale is that the software provided by the manufacturer in this case Lenovo/Motorola have it enabled, at this point my theory is that they disable it or enable it depending on some regional/country/carrier politics.
At this point enable it is not hard at all for the manufacturer, it´s enough with an update and include it as said @Droidriven
in a new kernel but I think that they are subject of what want finally a carrier.
Following this theory means that if device is a carrier branded that was provided directly by Lenovo to the carrier and this feature was blocked by software BUT if this device you bought it free of carrier out of the box in any cell store/shop then just the carrier that you are using didn´t enable this feature for this specific model (yet now but maybe in a near future) but it did it for other models.
To prove this last you could try with other chip/sim from other provider in an area that admits VoLTE.
I think that you are wording blacklisted wrongly, it´s not that your device is blacklisted to avoid this specific feature to working only on your device but all the Motorola G6+ under this carrier support.